For more system metrics, consider installing metricbeat on your hosts.

system.cpu.total.norm.pct

type: scaled_float

format: percent

The percentage of CPU time in states other than Idle and IOWait, normalised by the number of cores.

system.process.cpu.total.norm.pct

type: scaled_float

format: percent

The percentage of CPU time spent by the process since the last event.
This value is normalized by the number of CPU cores and it ranges from 0 to 100%.

system.memory.total

type: long

format: bytes

Total memory.

system.memory.actual.free

type: long

format: bytes

Actual free memory in bytes. It is calculated based on the OS.
On Linux it consists of the free memory plus caches and buffers.
On OSX it is a sum of free memory and the inactive memory.
On Windows, this value does not include memory consumed by system caches and buffers.